1. Field of the Invention
The invention is related to packet networks, and in particular, to a remote service testing system for monitoring the performance of packet networks.
2. Description of the Prior Art
Current packet networks support multiple types of communication services, such as voice, video, and data service. Voice over Internet Protocol (VoIP) calling is an example of a voice service that is growing rapidly in popularity. As communication services have advanced, the problems associated with providing such services over packet networks have expanded. For example, VoIP service is notoriously unreliable due to the distributed nature of packet networks. Another problem involves the difficulty of analyzing service performance across a modern distributed packet network.
One prior art solution for analyzing service performance requires placing a local probe on a network to monitor the activities of various nodes on the network. Packet sniffers are an example of a local probe used to monitor a network. Probes can be used to isolate network elements and investigate their real-time behavior. Unfortunately, a local access point for the probe is required because most routers and firewalls would otherwise block the probe from monitoring network activity.
FIG. 1 illustrates communication network 100 in an example of the prior art. Communication network 100 includes customer network 110, service provider network 120, and Internet 130. Customer network 110 includes VoIP enabled phones 101 and 102, and digital cross connect 103. Digital cross connect includes protocol analyzer 104. Service provider 120 includes router 121. Protocol analyzer 104 is an example of a local probe utilized to analyze whether or not elements of customer network 110 are operating correctly in accordance with communication protocols.
Service provider network 120 is an access network that provides access and service to elements of customer network 110. Digital cross connect 103 connects elements of customer network 110 to service provider network 121. Service provider network then provides access to Internet 130. In this example, service provider network 120 provides VoIP calling services to customer network 110. Callers place VoIP calls from phones 101 and 102. Digital cross connect 101 sends communications for the calls to service provider network 120. The calls are then routed over the Internet 130 to their respective destinations.
At times, users placing calls from phones 101 and 102 experience service problems. As illustrated by FIG. 1, a prior art solution is to place a local probe, protocol analyzer 104, on digital cross connect 103. Probe 104 can monitor the communications to and from phones 101 and 102. Additionally the probe can monitor the processes of digital cross connect 103. The cause of any service problems can be detected with the local probe.
This solution presents several problems for those concerned with network performance. For instance, a local probe is limited in the amount of data it can process. Furthermore, a local probe is unable to investigate packets on other networks other than the subject network. A local probe is also unable to correlate performance problems on other networks with problems on the subject network. In fact, local probes are often inaccessible from outside the network, thereby preventing outside monitoring capabilities and services, and are detectable by illegitimate sniffers and scanners.
Further problematically, if a probe is administered by a third party, such as a security firm or the service provider, the probe is often times inaccessible to the third party because it is located behind the customer's network firewalls and routers. Thus, the security firm, at best, is only able to periodically update the configuration of the probe. The local nature of probes in the prior art also prevents the probe from providing continual updates to the third party outside of the network. Third party security firms are prevented from fully analyzing the behavior of network elements. Instead, they are relegated to viewing sparse updates periodically transmitted from the local probes. Local probes also often times require inefficient and time consuming manual installation and operation.